Patents by Inventor Hirofumi Okuyama

Hirofumi Okuyama has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4555466
    Abstract: A developing material for electrostatic images comprising (a) carrier particles comprising iron beads coated with a layer of butadiene polymer resin in which Fe.sub.3 O.sub.4 powder is dispersed, the volume ratio of the polymer resin to Fe.sub.3 O.sub.4 is from 1:2 to 4:1, and the butadiene polymer is cured by heating with an organic peroxide of from 0.5 to 5.0 parts by weight, based on the weight of the butadiene polymer, which comprises a homopolymer containing 1,2-polybutadiene units, or a homopolymer or copolymer of cyclized 1,4-cis-polybutadiene and (b) from 1% to 6% by weight, based on the weight of the carrier particles, of toner particles which comprise a bis-phenol A-epichlorohydrin type resin, carbon powder, a nigrosine dye, and either a styrene-n-butyl acrylate copolymer or a montan wax.
    Type: Grant
    Filed: September 21, 1983
    Date of Patent: November 26, 1985
    Assignee: Fujitsu Limited
    Inventors: Seiji Okada, Isao Watanabe, Norio Sawatari, Kazumasa Saito, Toshiaki Narusawa, Hirofumi Okuyama
  • Patent number: 4547309
    Abstract: A storage type liquid crystal composition in which a nematic-cholesteric mesophase transition is utilized and the anisotropy of the dielectric constant is positive and an X-Y dot-matrix-type storage-type liquid-crystal display element comprising the composition. The present liquid crystal composition has low driving voltage and long memory effect. This composition comprises a cyclohexane-type liquid crystal, an azoxy-type liquid crystal, and a compensated cholesteric liquid crystal and/or cholesteryl oleate.
    Type: Grant
    Filed: December 6, 1983
    Date of Patent: October 15, 1985
    Assignee: Fujitsu Limited
    Inventors: Akihiro Mochizuki, Kasumi Ikegami, Toshiaki Narusawa, Hirofumi Okuyama
  • Patent number: 4522909
    Abstract: A process for preparing a developer for electrostatic images comprising: (1) immersing carrier beads in an organic solution of a resin material comprising a 1,2-butadiene or cyclized cis-1,4-butadiene homopolymer, or a mixture of at least one of the homopolymers and a styrene butadiene copolymer; evaporating the organic solvent of the solution, drying the immersed beads, and curing the resin material by a rotary drying method, to form a resin coating on the carrier beads; (2) blending toner materials at a temperature sufficient to form a toner mass, the toner materials comprising: (a) a binder resin, (b) a colorant, and (c) a charge controlling agent; and (3) pulverizing the blended toner mass to form toner particles and mixing the obtained toner particles with the coated carrier in a predetermined ratio of the total surface area of the carrier to the total projection area of the toner particles.
    Type: Grant
    Filed: June 7, 1983
    Date of Patent: June 11, 1985
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Narusawa, Seiji Okada, Kiyohide Muramatsu, Teruo Yagishita, Hirofumi Okuyama
  • Patent number: 4517266
    Abstract: A holographic recording material comprising a polymer containing vinylcarbazole rings, a cyclic cis-.alpha.-dicarbonyl compound capable of forming a radical by light irradiation and a dye as a photosensitizer or a spectral sensitizer. A hologram can be obtained by exposing the holographic recording material to an interference pattern of a radiation to form a holographic interference pattern, subjecting the material to a swelling treatment in a first medium, and then subjecting the material to a contraction treatment in a second medium.
    Type: Grant
    Filed: January 18, 1983
    Date of Patent: May 14, 1985
    Assignee: Fujitsu Limited
    Inventors: Kasumi Ikegami, Hirofumi Okuyama
  • Patent number: 4513075
    Abstract: A developer material for electrostatic images comprising a mixture of (1) a coated carrier and (2) a toner.(1) The carrier consists of core beads coated with a coating resin comprising a butadiene homopolymer of a molecular weight of from 10,000 to 100,000, for the butadiene homopolymer is 1,2-polybutadiene and/or cyclized cis-1,4-polybutadiene or a mixture of at least one of these homopolymers and a styrene/butadiene copolymer of a molecular weight of from 10,000 to 100,000, the mixture containing from 7.5 to 100% by weight, based on the weight of the mixture, of butadiene in polymerized form.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: April 23, 1985
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Narusawa, Seiji Okada, Kiyohide Muramatsu, Teruo Yagishita, Hirofumi Okuyama
  • Patent number: 4455361
    Abstract: A process for preparing a developer material for electrostatic images comprising a mixture of (1) a coated carrier and (2) a toner by a rotary drying method.(a) The carrier consists of core beads coated with a coating resin comprising a butadiene homopolymer of a molecular weight of from 10,000 to 100,000, for the butadiene homopolymer is linear 1,2-polybutadiene and/or cyclized as-1,4-polybutadiene or a mixture of at least one these homopolymers and a styrene/butadiene copolymer of a molecular weight of from 10,000 to 100,000, the mixture containing from 7.5 to 100% by weight, based on the weight of the mixture, of butadiene in polymerized form.
    Type: Grant
    Filed: February 9, 1981
    Date of Patent: June 19, 1984
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Narusawa, Seiji Okada, Kiyohide Muramatsu, Teruo Yagishita, Hirofumi Okuyama
  • Patent number: 4454213
    Abstract: A photosensitive material for electrophotography is provided which has a very high sensitivity to rays having a wavelength included in the oscillation wavelength region of a laser printer, especially a semiconductor laser printer, and which also has a high charge potential. This photosensitive material comprises a phthalocyanine pigment, poly-N-vinylcarbazole, and an organic resin in which said phthalocyanine pigment and poly-N-vinylcarbazole are dispersed, wherein the weight ratio of phthalocyanine pigment to poly-N-vinylcarbazole is in the range of from 1.2 to 12 and the content of the organic resin is 35% to 70% by weight based on the total amount of the photosensitive material.
    Type: Grant
    Filed: April 7, 1982
    Date of Patent: June 12, 1984
    Assignee: Fujitsu Limited
    Inventors: Teruo Yagishita, Seiji Okada, Toshiaki Narusawa, Hirofumi Okuyama
  • Patent number: 4362801
    Abstract: A photosensitive material for electrophotography having an improved photosensitivity is provided, which comprises copper phthalocyanine as a photoconductor, 2,5-bis(4'-diethylaminophenyl)-1,3,4-oxadiazole as a charge transport material and a binder resin in which said photoconductor and charge transport material are dispersed. The content of the binder resin is 50 to 70% by weight based on the total amount of the photosensitive material and the weight ratio of copper phthalocyanine to 2,5-bis(4'-diethylaminophenyl)-1,3,4-oxadiazole is in the range of from 2.5 to 6.5.
    Type: Grant
    Filed: October 9, 1981
    Date of Patent: December 7, 1982
    Assignee: Fujitsu Limited
    Inventors: Teruo Yagishita, Seiji Okada, Toshiaki Narusawa, Hirofumi Okuyama
  • Patent number: 3997463
    Abstract: A nematic liquid crystal composition, including p-methoxybenzylidene-p'-n-butylaniline, p-butoxybenzylidene-p'-n-butylaniline and bis(p'-n-octyloxy benzylidene)-chloro-p-phenylenediamine, has desirable thermodynamic properties, including a nematic mesophase over a wide temperature range, and also has a high dynamic scattering contrast ratio.
    Type: Grant
    Filed: March 21, 1975
    Date of Patent: December 14, 1976
    Assignee: Fujitsu Limited
    Inventors: Toshiaki Narusawa, Hirofumi Okuyama, Junjiro Goto, Yasuji Isozaki, Masatoshi Fujimori